I recently installed a used motor in my 97 accord. Upon startup it runs great till it's warm then if I snap open the throttle it shuts off. If I attempt to start it up it has to crank for a few then it fires up. I installed the new timing belt tensioner and water pump when it was out. Everything appears to be in time. With it running it's pointing to the timing mark to the left of the red mark. It idles fine both cold and warm. No codes are set. I checked the air filter and replaced the fuel filter. It had been sitting up for a few months. Any ideas?

 

was the engine confirmed good prior to installation ?

 

Yes engine was told to be a good one. If I open the throttle slowly it speeds up fine. I wonder if the catalytic converter being bad would cause this. I noticed that the center was melted out and pieces were falling out when I changed the exhaust.

 

Is the IACV functioning?
Was it just the long block(head/block) changed or did you use the intake/throttlebody/IACV/etc from the used engine?

 

It was a complete used engine. After gutting the bad converter it seems to run better but I'm still not 100% that was it.

 

compression test the motor to make sure it's in good shape

 

If you are using the used engines intake manifold then the IACV may not be workign properly, or the TB is gunked up not allowing enough air during idle.